isnan, isinf missing in uClibc environment

[wezm]

Building yajl on a uClibc based Alpine Linux machine failed with the error:

Linking C executable json_reformat
../yajl-2.0.3/lib/libyajl_s.a(yajl_gen.c.o): In function `yajl_gen_double':
yajl_gen.c:(.text+0x565): undefined reference to `__isnan'
yajl_gen.c:(.text+0x580): undefined reference to `__isinf'
collect2: ld returned 1 exit status

I fixed the issue by linking the json_reformat target with libm:

diff --git a/reformatter/CMakeLists.txt b/reformatter/CMakeLists.txt
index da4032b..d48e218 100644
--- a/reformatter/CMakeLists.txt
+++ b/reformatter/CMakeLists.txt
@@ -26,7 +26,7 @@ LINK_DIRECTORIES(${CMAKE_CURRENT_BINARY_DIR}/../${YAJL_DIST_NAME}/lib)

 ADD_EXECUTABLE(json_reformat ${SRCS})

-TARGET_LINK_LIBRARIES(json_reformat yajl_s)
+TARGET_LINK_LIBRARIES(json_reformat yajl_s m)

 # copy the binary into the output directory
 GET_TARGET_PROPERTY(binPath json_reformat LOCATION)

[royger]

Thanks for the patch!

Could this be added to yajl?

[royger]

The correct fix for this is the following, that compiles yajl with -lm when uclibc is detected, instead of having to add it to every program that depends on yajl:

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a1134d1..c3a4fad 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -54,6 +54,11 @@ ADD_LIBRARY(yajl_s STATIC ${SRCS} ${HDRS} ${PUB_HDRS})
 
 ADD_LIBRARY(yajl SHARED ${SRCS} ${HDRS} ${PUB_HDRS})
 
+IF(EXISTS "/usr/include/bits/uClibc_config.h")
+   target_link_libraries(yajl m)
+   target_link_libraries(yajl_s m)
+ENDIF(EXISTS "/usr/include/bits/uClibc_config.h")
+
 #### setup shared library version number
 SET_TARGET_PROPERTIES(yajl PROPERTIES
                       DEFINE_SYMBOL YAJL_SHARED

[volyrique]

Unfortunately, that is not the correct fix because it does not work when cross-compiling. The initial proposal works fine, though.